BOSTON (Reuters Health) - A cup of blueberries a day may keep
"senior moments" away, new findings suggest.

A team of Massachusetts and Florida researchers has shown that
the fruit reduces aging-related damage in rat brains, and can
also prevent mental decline in mice genetically engineered to
develop Alzheimer's-like plaques in their brains.

The findings, along with early results from a human study, suggest
a healthy diet can go a long way toward preventing the mental
decline that often accompanies aging, Dr. James A. Joseph of the
Center on Aging at Tufts University in Boston and USDA Human Nutrition
Research told Reuters Health.

Joseph presented his findings here Monday at the American Chemical
Society's annual meeting.

Cell-damaging products of normal metabolism known as free radicals
can injure tissue, an effect known as oxidative damage. Antioxidants
-- found in several fruits and vegetables, including blueberries
-- help prevent this damage, which has been implicated in a number
of conditions including cancer, Alzheimer's and heart disease.
Oxidative damage is also a factor in aging.

Aged rodents that consumed the human equivalent of one cup of
blueberries a day showed less oxidative damage in tissue from
two distinct brain regions, Joseph and his team found.

To evaluate whether this effect might extend to behavior, Joseph
and colleagues David Morgan, Gary Arrendash and David Diamond
from the University of South Florida, put mice through a three-armed
maze.

Half of the mice were genetically engineered to develop Alzheimer's-like
plaques in their brains, while the rest were not. In each group,
half of the animals were given blueberry-based pellets.

Testing began when the mice were young, before the genetically
modified animals had developed plaques. The study lasted a year.

The mice with pseudo-Alzheimer's that didn't eat blueberries
performed worse and worse on the maze over time. But the genetically
modified animals given blueberries showed no decline; they performed
just as well as normal mice, even though they still developed
plaques.

Joseph said he believes the berries' brain-protecting power
goes beyond its known antioxidant and anti-inflammatory effects.
Blueberries seem to "directly influence the way neurons communicate,"
he told Reuters Health.

Preliminary results from a new study, he added, show that people
who ate a cup of blueberries a day appeared to be protected from
aging-related mental decline. Joseph expects the study will be
published late this fall.

The next steps, the Boston researcher said, will be to do more
tests in transgenic animals, evaluate which chemicals in blueberries
find their way into the brain, and study how the fruit might be
protecting the brain.